Provided are: a hydrocarbon adsorbent capable of adsorbing hydrocarbons, storing the adsorbed hydrocarbons up to a relatively high temperature, and desorbing the adsorbed and stored hydrocarbons at a relatively high temperature; an exhaust gas purifying catalyst composition using the same; an exhaust gas purifying catalyst; and a method for treating an exhaust gas. The hydrocarbon adsorbent comprises a zeolite having an MRT-type framework structure. The hydrocarbon adsorbent comprises a small-pore zeolite having a total desorption amount ZD.sub.1 of propylene desorbed at 50° C. or higher and lower than 300° C. being 3.5 mmol/g or less and a total desorption amount ZD.sub.2 of propylene desorbed at 300° C. or higher and 500° C. or lower being 0.5 mmol/g or more, per 1 g by mass of the small-pore zeolite, when adsorbing propylene at 50° C. and then heating from 50° C. to 500° C. under the condition of 10° C./min by a temperature-programmed desorption method.

A packaging film is described comprising at least one polymer film layer in which particles of a small-pore or a medium-pore palladium-doped zeolite are dispersed. Such films are of particular utility for the adsorption of volatile organic compounds, such as those originating from organic matter.

An adsorbent having a microwave absorption property is provided. The adsorbent having an improved microwave absorption property, which has a core-shell structure including a silicon carbide bead disposed therein, and an adsorbing material disposed outside the silicon carbide bead, can be provided. Also, the adsorbent may further include a plurality of silicon carbide particles dispersed and disposed therein and having a diameter of 1 μm to 10 μm, and the adsorbing material may be ion-exchanged with a cation. Therefore, the adsorbent can be useful in improving desorption efficiency since the adsorbent may be rapidly heated by microwaves to reach the desorption temperature due to high reactivity to microwaves. Also, the adsorbent can be useful in maintaining full adsorption capacity without having an influence on adsorption quantity since the silicon carbide bead is disposed in the inner core of the adsorbent. Further, when the adsorbent is applied to conventional systems for removing organic compounds using microwaves or dehumidification systems, the adsorbent can be semi-permanently used, and may also have an effect of enhancing the energy efficiency by 30% or more, compared to adsorbents used in the conventional systems.

The present invention concerns the use, for gas separation, of at least one zeolite adsorbent material comprising at least one FAU zeolite, said adsorbent having an external surface area greater than 20 m.sup.2.Math.g.sup.−1, a non-zeolite phase (PNZ) content such that 0<PNZ≦30%, and an Si/Al atomic ratio of between 1 and 2.5. The invention also concerns a zeolite adsorbent material having an Si/Al ratio such that 1≦Si/Al<2.5, a mesoporous volume of between 0.08 cm.sup.3.Math.g.sup.−1 and 0.25 cm.sup.3.Math.g.sup.−1, a (Vmicro−Vmeso)/Vmicro ratio of between −0.5 and 1.0, non-inclusive, and a non-zeolite phase (PNZ) content such that 0<PNZ≦30%.

Provided is an adsorbent for removal of iodide ions and iodate ions, which exhibits excellent adsorption performance of iodide ions and iodate ions. An adsorbent according to the present invention comprises cerium(IV) hydroxide and a poorly soluble silver compound. It is preferable that the content of cerium(IV) hydroxide is 50% by mass or more and 99% by mass or less, and the content of the poorly soluble silver compound is 1% by mass or more and 50% by mass or less. It is also preferable that the poorly soluble silver compound is at least one selected from silver zeolite, silver phosphate, silver chloride, and silver carbonate.

A hydrocarbon adsorbent having high hydrocarbon adsorbing properties even after exposed to a high temperature/high humidity reducing atmosphere, includes a FAU type zeolite having in ESR measurement a spin concentration of a least 1.0 × 10^19 (spins/g) and a ratio of a peak intensity at a magnetic field of at least 260 mT and at most 270 mT to a peak intensity at a magnetic field of at least 300 mT and at most 320 mT of at least 0.25 and at most 0.50 Å and containing bivalent copper. The hydrocarbon adsorbent may be used for a method for adsorbing hydrocarbons to be exposed to a high temperature/high humidity environment, and may be used particularly for a method for adsorbing hydrocarbons in an exhaust gas of an internal combustion engine, such as an automobile exhaust gas.

A composition is provided that has heat resistance sufficient for use as a hydrocarbon adsorbent and desorbs hydrocarbons slowly with respect to an increase in temperature. The composition includes an alkali metal and a zeolite having a YFI structure. A content of the alkali metal is 1 to 40 mass% based on a total mass of the composition, and a content of the zeolite having a YFI structure is 99 to 60 mass% based on the total mass of the composition.

A porous activated asphaltene material is described with a method of making and a method of using for the adsorption of a contaminant from a solution. The porous activated asphaltene material may be made by functionalizing solid asphaltene with nitric acid, and then treating the product with a metal hydroxide. The resulting porous activated asphaltene material exhibits a high porosity, and may be cleaned and reused for adsorbing contaminants.

The invention relates to modified zeolite crystals comprising zeolite crystals and from 0.5% to 20%, by weight, endpoints included, relative to the total weight of modified zeolite crystals, of at least one polymeric compatibilizer, more particularly a functional polyolefin.

The invention also relates to the use of the modified zeolite crystals according to the invention as a filler in a polymer matrix, for example for the preparation of composite materials.

The use of a palladium-doped zeolite for the adsorption of volatile organic compounds is described wherein the zeolite has a CHA framework type and is polymer-bound. Such zeolites have been found to have particular utility as packaging materials for the adsorption of volatile organic compounds, such as those originating from organic matter.